Nevada Scientist Makes Adaptation Discovery

8/19/2009 - By: Mikalee Byerman

Questions involving adaptation and genetic mutation have new answers through the work of Chris Feldman, research scientist in the University of Nevada, Reno’s College of Agriculture, Biotechnology and Natural Resources, and peers from Utah State University and the University of Virginia.

The scientists have discovered that garter snakes, Thamnophis, took more than one path to adaptation as they evolved resistance to a powerful neurotoxin found in Pacific newts, Taricha — a favorite food of the snake.

The findings appeared in the July 28 issue of the Proceedings of the National Academy of Science. The research — conducted by Nevada’s Feldman, a scientist in the University of Nevada, Reno’s Department of Natural Resources; USU biology professor Edmund Brodie, Jr.; Brodie’s son, Edmund Brodie III of the University of Virginia; and Mike Pfrender, USU associate professor of biology — is funded by the National Science Foundation.

“There are so many outstanding questions in evolution, and this helps us understand one aspect much more clearly,” Feldman said. “We looked at three different species of the garter snake and found three different ways that they’ve adapted to the same challenge.”

The broader implications: Feldman’s research could provide clues about how species adapt at a genetic level to environmental stressors like climate change, drought, pesticides and pollution.

“The common thought with insecticide resistance, for instance, is that the first time you apply an insecticide, it might take five, 10 or 15 years for a species to become resistant,” Feldman said. “But research suggests that some insects may already have the beneficial genetic mutations needed to overcome pesticides, and those mutations can develop into adaptations when they become useful to the insects in overcoming pesticides.”

The garter snake species studied are able to consume the poisonous newts with no negative effects.

“These are newts that are so poisonous, they would kill you and me — some newts have enough toxin to kill a dozen people,” Feldman said. “Yet these small snakes, weighing less than a pound, are nearly immune to the poison — some can deal with enough toxin to kill 900 people.”

The Nevada scientist presented the research at the 2009 Joint Meeting of Ichthyologists and Herpetologists in Portland, Ore.

“This research is remarkable because it illustrates that a simple genetic change can underlie major differences in how animals cope with their environment,” Feldman said.